Earl, Michael J.
Prentice-Hall, 1989
Buku Teks
Cashmore, Carol
Prentice-Hall, 1991
Buku Teks
Smallwood, Robert F
Bacchus Books, 2016
Buku Teks
[Fakultas Ilmu Komputer Universitas Indonesia, Fakultas Ilmu Komputer Universitas Indonesia], 2009
Artikel Jurnal
by E. Wainright Martin ... [and others]
Prentice-Hall, 1999
Buku Teks SO